In wireless communication networks, such as, for example, a Long Term Evolution (LTE) 3rd Generation Partnership Project (3GPP) network, the quality of service (QoS) provided to each bearer in the network is typically managed on a per bearer level from the core network. The Radio Access Network (RAN) is usually responsible for setting up radio bearers, radio resource management and enforcing a QoS level according the bearer's QoS profile. During the triggering of handover events, such as, for example, when a wireless device user moves from an outdoor/macro system to an indoor/enterprise system, the QoS profile for each bearer may need to be updated to reflect the user's new region. This results in bearer modification, which can lead to such problems as service interruption.
For example, a wireless device user is using data traffic on a bearer having a QoS Class Identifier (QCI)=x while connected to an outdoor, or macro, system. The user moves indoors to connect to their indoor, or enterprise, system and a handover will occur, assigning the same QoS profile (QCI=x) to the bearer as used for the macro system. A location event is reported to a policy and charging rules function (PCRF) entity, which, if a higher QoS level on the indoor system is desired, triggers a bearer modification to a higher QoS profile i.e., QCI=y. This implies a QoS upgrade on the indoor RAN.
When the user leaves the indoor system, another handover procedure will request the same QoS profile that was assigned to the bearer while the wireless device user was connected to the indoor system. However, if the target macro base station is not configured to support an enhanced QoS profile, i.e., QCI=y for that particular bearer, either a different QCI is selected by the target e-Node-B (eNB), or the handover will be rejected and the bearer torn down. In some cases, a default QCI may be applied, which could be associated with the lowest available QoS level, which can lead to inadequate user service. Further, when a location event is reported back to the PCRF entity, a bearer modification may trigger an update back to the macro QoS profile, i.e., QCI=x, which was the original QCI used on the macro system. During the bearer modification process, data traffic will be interrupted. A “ping pong” effect can also take place where bearers are bounced back and forth between the indoor and outdoor systems, further interrupting traffic.
There is shown in FIG. 1 a block diagram of a known LTE QoS 4th Generation (4G) network. In a wireless communication system such as the one shown in FIG. 1, services are provided to a subscriber on radio bearers. Bearers are the logical connection that carry audio, video, data, and/or control signaling between a network node, such as a mobile management entity (MME), and a base station or between a base station and a wireless device, e.g., user equipment (UE), of a subscriber. Bearers, including a QoS profile for each bearer, are set up from the PDN GW in the core network (CN) and the QoS is enforced in the PDN GW and in the eNB for the downlink and in the wireless device, i.e., UE, and the base station, i.e., eNB, for the uplink. The bearer can be either a dedicated bearer, which carries specific data flows to/from a wireless device, or a default bearer, which handles all traffic not specified for a dedicated bearer to the wireless device. The present disclosure applies to location-based QoS differentiation of traffic on both default and dedicated bearers.
As used herein, the term “QoS profile” refers to a set of values including, e.g., a QCI value, that are assigned to a bearer to indicate a corresponding QoS level to be realized or enforced for the bearer. Moreover, as used herein, the term “QoS level” refers to a result, e.g., a high QoS or a low QoS, that is realized. The QoS level is typically realized using a set of corresponding QoS parameters, e.g., a minimum throughput rate parameter, an error rate parameter, a scheduler priority etc., stored at and enforced, e.g., by the base station. The correspondence between different QoS profiles and their corresponding QoS levels and corresponding sets of QoS parameters may be configured by an operator of the RAN.
In FIG. 2, a bearer modification procedure for an LTE system according to the prior art, is shown. In the illustrated procedure, after an exchange of measurement control signals and measurement reports between a UE and a source eNB, a handover decision is made (step 3) and the source eNB sends a handover request to the target eNB. Included in the handover request is the bearer QoS profile applied in the source eNB. The target eNB then makes an admission assessment (step 5) and if granted, sends a handover request acknowledgment back to the source eNB in step 6. A bearer modification is triggered every time the QoS profile needs to be updated. As discussed above, bearer modifications can lead to service interruptions.